Itchy Penis, Spreading Red Marks On Penis Head. What Are These Marks?

Hello...about a week ago...my penis became very itchy...there was no signs of anything there so i just assumed it was from being dry since i work alot with drywall and the dust causes dry skin . but a couple of days ago, i noticed on the head of my penis a couple of red pimplelike marks. now it has seemed to have gotten worse. there are many little pimplelike marks and a couple of bigger ones and seems to be spreading down the shaft more...its increadibly itchy...Im married and havent had sex with anyone other than my wife in years and she has no symptoms...she thought i maybe had an std ...and we recently had a baby and she was checked and is negative for stds...also around the infected area...some of the skin on the pimples is peeling a little.